atomics-sema-alignment.c
1.95 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
// RUN: %clang_cc1 -triple aarch64-linux-gnu %s -emit-llvm -o /dev/null -verify
typedef struct {
int a, b;
} IntPair;
typedef struct {
long long a;
} LongStruct;
typedef int __attribute__((aligned(1))) unaligned_int;
void func(IntPair *p) {
IntPair res;
__atomic_load(p, &res, 0); // expected-warning {{misaligned atomic operation may incur significant performance penalty; the expected alignment (8 bytes) exceeds the actual alignment (4 bytes)}}
__atomic_store(p, &res, 0); // expected-warning {{misaligned atomic operation may incur significant performance penalty; the expected alignment (8 bytes) exceeds the actual alignment (4 bytes)}}
__atomic_fetch_add((unaligned_int *)p, 1, 2); // expected-warning {{misaligned atomic operation may incur significant performance penalty; the expected alignment (4 bytes) exceeds the actual alignment (1 bytes)}}
__atomic_fetch_sub((unaligned_int *)p, 1, 3); // expected-warning {{misaligned atomic operation may incur significant performance penalty; the expected alignment (4 bytes) exceeds the actual alignment (1 bytes)}}
}
void func1(LongStruct *p) {
LongStruct res;
__atomic_load(p, &res, 0);
__atomic_store(p, &res, 0);
__atomic_fetch_add((int *)p, 1, 2);
__atomic_fetch_sub((int *)p, 1, 3);
}
typedef struct {
void *a;
void *b;
} Foo;
typedef struct {
void *a;
void *b;
void *c;
void *d;
} __attribute__((aligned(32))) ThirtyTwo;
void braz(Foo *foo, ThirtyTwo *braz) {
Foo bar;
__atomic_load(foo, &bar, __ATOMIC_RELAXED); // expected-warning {{misaligned atomic operation may incur significant performance penalty; the expected alignment (16 bytes) exceeds the actual alignment (8 bytes)}}
ThirtyTwo thirtyTwo1;
ThirtyTwo thirtyTwo2;
__atomic_load(&thirtyTwo1, &thirtyTwo2, __ATOMIC_RELAXED); // expected-warning {{large atomic operation may incur significant performance penalty; the access size (32 bytes) exceeds the max lock-free size (16 bytes)}}
}